Front strut tower brace

[D2M]

Just an FYI. If for whatever reason the OEM front strut brace must be removed be sure to readjust the preload. The strut brace has some negative preload adjusted into it from the factory. Once removed you will notice that the old witness marks no longer line up when reinstalling the brace. The big adjustment nuts must be loosened and the brace made longer, then bolted down in the same location, then the big center nut could be tightened to make the brace shorter pulling the strut towers together. Mine had about 1 turn of preload from the factory. Before I loosened the adjustment nuts I took a measurement to put back the correct amount of preload. I'm sure this measurement will be unique to every car.

 

[MCN1SMO]

Yeah I've had mine off and on a few times and noticed it needed a turn

Replaced it with this

 

[D2M]

I wonder if the preload has any affect on anything? All aftermarket and Nismo upgrade bars don't have any adjustment, they just bolt in place.

 

[MCN1SMO]

I wonder if the preload has any affect on anything? All aftermarket and Nismo upgrade bars don't have any adjustment, they just bolt in place.

They also don't require for the suspension to even be unloaded with the car in the air. You can install on the ground

 

[goeagles11]

Uhh I removed and re-installed mine while the car was on the ground. Do I need to jack it up and re install it?

 

[D2M]

Uhh I removed and re-installed mine while the car was on the ground. Do I need to jack it up and re install it?

No, just loosen the 2 big jam nuts then loosen one side on the brace, turn the big center nut 1 turn to extend the brace, tighten the one side you loosened then crank in 1 turn of preload on the big center nut and re tighten the 2 big jam nuts.

 

[Hernandooo]

Does anyone know what the torque specs are for tightening the struts?

 

[MCN1SMO]

Does anyone know what the torque specs are for tightening the struts?

I think its like 35? does that sound right. I think that is what was on the NISMO instructions when I did mine

 

[David Montgomery]

If I take it off and put it back on without adjusting it, what will that do?

 

[FSUZ33]

Only removed mine once, but a handful of times on my Z33’s. I always loosen the lock nut and remove the preload before removing the hardware. Maybe I was unlucky, but the first time I removed it on my ‘03 I didnt do that, it flexed out a little when loosening the hardware and boogered the threads a little on a couple of the screws. Unfortunately I didn’t catch it and tried to reinstall them, galling two of the inserts. Had to buy a tap and clean them out. on my 2nd 350 and my current Z I added anti seize on all the first time I removed them to try and avoid issues (To the mounting how, not the adjustment screw and nuts).

My personal opinion, not preloading an adjustable bar, especially a factory one that’s gotta be 30 lbs, isn’t going to change anything enough to ever notice. Not preloaded you probably will get a miniscule amount of initial bar deflection right when it loads up that you wouldn’t get if preloaded, but my opinion it’s not enough to remotely worry about.

 

[KrackaC8]

After R&R, I tensioned mine back to factory-ish, or maybe roughly a half-turn tighter. More or less, I discovered it was adjustable and just wanted to mess around with it to see how it worked. Its a very good design from the factory and likely stiffer/stronger than most the aftermarket offerings (trade-offs being weight and not looking very nice).

 

[FSUZ33]

This is a little 'particular' but since I messed up the inserts forever ago and had to clean up a couple of the screws I have a procedure when removing and reinstalling the front bar. In short, I adjust the span so that the holes in the bar mounts aren't touching the threads of the hardware.

Loosen the jam nut and release the preload.
Remove all hardware & bar.
...
Replace the bar and tighten the screws and nut on one side with the hardware centered in the mounting holes.
Adjust the overall bar link length with the adjustment screw so the hardware is centered in the mount holes on the other end.
Install/tighten hardware.
Add preload (doesn't need much) and tighten jam nut.

The mounts probably won't move at all once everything's tight, and I realize this is overthinking/overdoing, but I don't like the thought of the end brackets constantly loading and unloading while touching the threads of the hardware.

 

[David Montgomery]

This is a little 'particular' but since I messed up the inserts forever ago and had to clean up a couple of the screws I have a procedure when removing and reinstalling the front bar. In short, I adjust the span so that the holes in the bar mounts aren't touching the threads of the hardware.

Loosen the jam nut and release the preload.
Remove all hardware & bar.
...
Replace the bar and tighten the screws and nut on one side with the hardware centered in the mounting holes.
Adjust the overall bar link length with the adjustment screw so the hardware is centered in the mount holes on the other end.
Install/tighten hardware.
Add preload (doesn't need much) and tighten jam nut.

The mounts probably won't move at all once everything's tight, and I realize this is overthinking/overdoing, but I don't like the thought of the end brackets constantly loading and unloading while touching the threads of the hardware.

I know this sounds crazy, and it makes me seem like a dolt, but can you send a picture that identifies which nut on the bar is which? I see three and want to ensure I am tightening the correct bolts.

 

[KrackaC8]

I know this sounds crazy, and it makes me seem like a dolt, but can you send a picture that identifies which nut on the bar is which? I see three and want to ensure I am tightening the correct bolts.

Outer two are lock nuts, center is the adjustment. Loosen the outer two to adjust the center, then retighten the outer two.

 

[VR30Infection]

This broke my brain. My understanding is that a strut tower bar is there to keep the chassis from flexing. Why would we want a preload on the bar creating an inward flex. Wouldn’t we want the support be keeping the strut towers from flexing inward toward each other ? . Thoughts?